PlanetZ forums - scopeusers.com

I had to fix the MOD button on this a long time ago.



BTW, I really prefer the sound of the Profit 5 and Pro Wave. I think the hardest part would be emulating the filter.

-Tom

Forgive my ignorance, Canuck, but what the heck is it?

Lol. It's a Jupiter 6

Very basic synth. The U Know 007 should be modelling the same filter as they use the same IC.

-Tom

its just a basic ota design 4 ota in package with resonance feedback

the jupiter 6 uses a saw vco core with waveshapers similar to the jupiter4 ir309 is the 4 cascading ota as 4 gain cells

you can accomplish this in modular using 4 linear vca controled via a frequency scale which has an expo curve

the juno is based on a dco which has a digital control of a square wave this then goes through a waveshaper a ramp waveshaper

and flipflop for the sub oscillator the osc is a analog voltage oscillator its controlled digital so that its more stable

but it is only a single oscillator so all the oscillator waveforms are in phase as they start at the same phase

the roland filter is very basic filter and is a very polite filter compared to ssm and cem and moog designs

there 4 ota design they have used from the roland 700 modular sysatem but back then they created custom ba662 single ota

later on in the juno and jupiter they made an asic with 4 in the juno is a design chip that had descrete based on using carbon smd resistors ad transistors and ota then they put resin on them but the resin fails and causes the cracks in the solder joints the clones use lm13600 dual ota based on dual ca3080 ota and you cant tell the difference in sound

there are a lot of synths with filters that use the ota as gain cells the oberhiem sem uses 2 as an svf filter topology

Thanks for the info jhulk! That's very interesting. You know a lot more about the old synths than me lol.

I had no idea that the Jupiter filter is a lot easier to simulate than the other ones.

I am really not crazy about the sound of the JP6, I just miss the sliders and pots. Oh, and blinking lights!



-Tom

I should really sit down and play with Modular 4. But all these Scope devices are giving me ADD

-Tom

I always enjoyed the whackier side of the JP-6, but ultimately the sound of the JP-4 is what I always loved so I bought one and hope for a decent emulation one day. It's a simple synth in terms of features, but it just has a great sound.

Simple can be good! I think that's why I liked the JP6. It was pretty basic.

-Tom

yes its a 555 timer circuit and makes a very good square wave oscillator they use flipflops for the sub tones

the jupiter4 is a very stable oscillator as it uses a ua726 heater transistor mirror pair

there is a new 555 oscillator designed by thomas henry and its the closest to a cem3340 there is

the jup 4 depending on what model has 4 ba ota in the revision 1/2 filter cores the ba ota they had problems at manufacture where some became lesser spec than others which made matching them tedious so the revision 3 boards used a new designed chip which was 4 matched ota in one chip this is the chip in the jup6 and 8

the jup 4 is a nice sounding synth and i think its the best sounding out of the roland poly but again its a single oascillator synth which limits it

the jup4 is all about the interface the jupiter4 is a really pain in that because it became computer controlled its does things long winded it has 4051 multiplexers that sample and hold the sliders this is sent digitally to the cpu via the abc outputs

this allows for it to have presets then the cpu sends the digital data back to a set of 4051 sample and holds which sends the cv voltages to the chips the biggest problem with these systems is that when you press a preset the knobs are never where they are which is the biggest problem with poly synths of that era

but i have the schematics and have access to a jup4 ill sample the waveforms and send to simon and see if he can wavshape an oscillator to have the same wave shape see if we can get a jup4 oscillator in to bc modular

I'm pretty sure Paia uses the 555 for their Fatman. I wasn't too impressed with their demos.

I built a 2 VCO with sync, LFO and a Moog ladder a very long time ago. That's was the first synth I built. I don't know what happened to the synth DIY community, but it seems to be gone! Tom G from Electronics For Music had lot of good schematics and circuit layouts. I even bought some PCBs from him. Can't find anything about him anywhere. I still have a partially populated Mad Mouse, but it's missing the MIDI PIC. I believe it uses a diode ladder filter. Never finished it, so no idea what it sounds like. I can read schematics and solder, but I am not an engineer. I have a math degree.

There was also Jim Patchman (may be a bit off), who was building a huge single panel modular. His stuff was crazy.

Well, Oakley is still around, but a bit pricey. Still have their TB3030 v2 PCB with the rare parts kit.

-Tom

its not gone its viral

muffwiggler is the place now

im building the new 4x4 modules which have serge the thomas henry 555 oscillator and modules by the late haible

old crow is doing some great stuff new minimoog crowbx 4 voice and 8 voice moduler obx

and cs80 modules

if you got the jup6 sample the oscillators for a few seconds just raw no modulation and filter fully open

for each waveform and do some of pwm we can then take those and waveshape a oscillator modular module to have the same waveform sound

Oh, so I was cool 12 years ago

lol

-Tom

I don't have the Jupiter anymore. Should have sampled it before I sold it, sheizer.

-Tom

I could sample the CEM3340 if I bought it on eBay for a crazy price of $100. Why so expensive? It's just a chip.

-Tom

Found raw waves that someone sampled. You might want to have a look.

http://privat.bahnhof.se/wb447909/phono ... EM3340.rar

-Tom

Apparently the same VCOs were used on the Prophet 5 rev3. According that that site...

-Tom

got those i sampled my memorymoog

for the cem3340

i forgot that they used he cem chip for that but kept the roland filters

that oscillator is already available in bcmodular its the multi osc it was done about 14 months ago

its done on the memory moog type ramp tri pwm/square in phase wave forms at same time and has a master and slave version

so now i need to make a 4 cascade gain cell filter with resonance

i have also done the alphajuno1/2 dco samples must post them to simon for a oscillator

me and sharc have worked on a few oscillators but what ones he is releasing next i dont know but we had fun with one from an old poly and mono synth

Do I need to buy Flexor to use BC Modular? I'm not sure how it works.

Thanks,

-Tom

no even though flexor is nice a lot of the modules only allow mono or very li8mited polyphony 1-3

bc modular is free and is a community project that sharc does he creates the modules if you have new ideas for new modules you can put forward the ideas to sharc who will try and create the modules and add them to bcmodular updates

then there is wills who does the scope sync part with shark

go over to the bcmodular forum and download the latest version there are over 400+ modules

and he has circuit level modules that you can create your own with like the sdk but with out the sdk

that with the sdk can be made into new modules

Sounds nice!

I will try it out when I get the chance. I have the SDK 5.1...

-Tom